dictionary – el diccionario
(Pronounced deek-syoh-nah-ryoh)
To remember that dictionary is pronounced deek-syoh-nah-ryoh (diccionario) in Latin American Spanish, use the following mnemonic:
I checked the dictionary for the right word, and I declare that the man I see over there is a nasty lothario (diccionario).
Diccionario is masculine, so it's el diccionario. Imagine an elephant looking up the word trunk in a dictionary.